I have a problem (or maybe do something wrong) with common error ‘Object has wrapping UVs’.
First of all I create sketch-level from BSP-brushes, set textures, and then convert BSP to StaticMeshes. And got this problem (‘Object has wrapping UVs’).
Ok, I google for solution for this problem, and found it.
After changing lightmap index from 0 to 1 → Apply Changes → Save Mesh I see this:
Converting BSP in static mesh have bug. You need open mesh editor and input any value in Light Map Resolution. This parameter located in Static Mesh Setting in Details. But you changed Min Lightmap Resolution this is no right. In my previous picture Light Map Resolution marked with number 3.